Analysis of future saline intrusion in a coastal aquifer as a response to climate change. Partido de la Costa, Buenos Aires province

Acta geológica 24 (1-2):2012

Abstract

According to the IPCC fourth assessment report, sea level rise would be one of the more certain effects of global climate change and salt water intrusion into coastal aquifers would be an important impact of sea level rise. The methodology proposed by Werner and Simmons (2009) following Custodio (1987) was used to quantify the increase in salt water intrusion length into the coastal aquifer at Partido de la Costa, Buenos Aires, Argentina. The flux-controlled model, which does not decrease the freshwater lens but shifts it upward, suggests that the salt water intrusion length will increase by 25, 33 and 38 meters depending on aquifer recharge scenarios and considering a one meter sea level rise. Results from the head-controlled model, which is based upon a reduction in the size of the aquifer with sea level rise, show a much greater increase in the salt water intrusion length of 193, 199 and 211 meters for the used parameters. If the constant-flux model is met the coastal aquifer under investigation will not be greatly affected by different sea level rise or water consumption scenarios. However, if the constant-head model is the case, which is more likely due to the low elevation of the land surface, an increase in salt water intrusion length by more than 200 meters will severely degrade the aquifers, forcing coastal managers to adopt a careful freshwater management for the resident’s water supply.